I've used professional movers for a cross-country move and had reasonable luck. Anticipate that a thing or two might get broken and you won't feel let down. I also recommend that you give an accurate estimate about what you plan to take. Speaking with (ethical) movers, they say that people often get upset when the price goes up because of unplanned items.
For one move, I used PODs. You need a driveway or space to put them. The cost of a cost country move can be cut almost by half, even if you hire loaders and unloaders on either end of the move. I was pretty satisfied with the result. Don't load the thing yourself. The professional crews make good use of the space and end up saving you money by making full use of the pod.
Even cheaper: rent a truck and hire movers to load the truck for you. They will be able to pack it better than you can, and then you can just drive it to your destination. Just make sure you're comfortable driving a big truck across the country.
Or, if you just graduated residency and are taking a new job, just purge your things and start buying nice things instead.
